Superlative form of high-risk: most high-risk.(adjective)
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Use "highest-risk" in a sentence
"Eleven management units were identified as highest-risk and highest-threat."
"Several other Asian countries made it into the highest-risk category, including the Philippines at 6 on the list, Vietnam at 13 and Pakistan at 16."
"The union said Friday the documents, obtained by the NLRB under a subpoena in the legal battle, demonstrate that Boeing decided to open a second assembly line for its 787 Dreamliner jet in North Charleston, S.C., to avoid labor problems, even though Boeing officials considered the location its highest-risk option."